Hamed Mahdavian Mehr; Arash Koocheki; Mohebbat Mohebbi
Abstract
Introduction:Deep fat frying is a cooking method where oil is used as the heat transfer medium, in direct contact with food at a temperature above boiling point of water. The aim of this process is to combine short cooking times with unique characteristics. It also involves heat and mass transfer simultaneously. ...
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Introduction:Deep fat frying is a cooking method where oil is used as the heat transfer medium, in direct contact with food at a temperature above boiling point of water. The aim of this process is to combine short cooking times with unique characteristics. It also involves heat and mass transfer simultaneously. During frying time, the mass transfer is characterized by the dynamics moisture loss from the food and the fat uptake into the food. There is some experimental evidence showing that water loss and oil absorption are correlated and progress with specific kinetic. In the meantime, oil uptake of product is an important issue, affecting the nutritional and organoleptic qualities of fried foods. However, one problem associated with fried foods is the considerable amount of oil absorbed during the deep frying process. It is affected by oil temperature, frying time, initial water content of food ingredients, product surface area, the ratios of product weight to frying oil volume, pretreatments and many other factors. So far, several approaches have been suggested for decreasing oil uptake during deep frying of fried foods. One way to decrease oil absorption in foods is referred to batter coating. In this regard, the ingredients and flow behavior's properties of batter are the most important parameters to determine the performance of batter coating and reduction of oil uptake in the final product. In the batter formulations, proteins and gums can be used as important and effective components, because they have great water bonding and barrier properties, which has strong impact on reduction of oil uptake during frying. Therefore, the objective of the present study was to assess the effects of replacement of Godume shahri seed gum (0.5 and 1%) or soy protein isolates (2 and 4 %), as part of the wheat flour in batter formulation, on rheology of batter, batter pickup and mass transfer kinetic parameters during deep frying of chicken nuggets.Materials and method:Raw materials including fresh chicken breasts, onion, salt, hot pepper, wheat flour, baking powder, and 100% pure sunflower oil were purchased from local markets. SPI (92% protein. w/w, db) were obtained from FSL Co. The batter formulations consisted of wheat flour, salt (1.5% w/w, db), baking powder (0.5% w/w, db), SPI (2 and 4% w/v, db) and Godume shahri seed gum (0.5 and 1%). For all samples, water/dry mix proportion had always been 5:3.Rheological properties of the batters were carried out using a Bohlin rotational Viscometer. For each test, shear rate increased from 0 to 300 s−1. The flow behavior index (n) and consistency coefficient (k) values were computed by fitting the power law model.The chicken nuggets, containing a mixture of chicken breast meat (88%), onions (10 %), Pepper (0.5%) and salt (1.5 %) were prepared in slab shapes using a manually operated cutting device. The dimensions of the chicken nuggets were about 4.5 cm (length) × 2.6 cm (width) ×1.1 cm (thickness) (±0.2 cm). Batter pickups (%) were calculated by the weight difference between the chicken nuggets after coating to the weight of chicken nuggets before coating. Deep frying was performed in programmable deep fat fryer contained 1.5 L refined sunflower oil. Samples were placed in a wire basket and then submerged for the required times of zero, 1, 2, 3, 4 and 5 minutes at 150 ◦C, 170 ◦C, and 190 ◦C. Oil and moisture content of the chicken nuggets were determined by standard techniques. For modeling moisture and oil transfer phenomena in fried chicken nuggets, Fick’s law of diffusion and a first order kinetic model were used respectively.Results and Discussion:Results showed that Godume shahri seedgum had more effect on apparent viscosity compared with soy protein isolates. Polysaccharidic structure of Godume shahri seed gum prepares high number of hydroxyl groups. Hydrodynamic interactions between polar and hydrophobic groups trap most of the free water and consequently increase batter viscosity. All batters showed shear thinning behaviour (n≥0.529). The power law model was adequately suitable to describe the flow behavior of the batters (R2≥0.994). Coating uptake at the surface of nuggets was significantly affected by the batter consistency. The consistency index for batter containing gum was high and therefore the coating uptake was higher for these samples. The maximum moisture loss rate and the effective diffusion coefficient obtained for chicken nuggets coated with only batter. Addition of soy protein isolates and Godume shahri seed gum to batter formulation, decreased the Deff to 3.55-5.46×10-8 m2/s and 3.38-5.32×10-8m2/s, respectively. This can be attributed to the effect of different batter formulations and special functions of gum and protein. The activation energy to remove moisture and oil absorptionwere 10.79 (kJ/mol) and -7.91(kJ/mol) for the control sample, 13.37-17.64 (kJ/mol) and -5.90 to -9.18 (kJ/mol) for soy protein isolates and 11.9-14.7 (kJ/mol) and -7.56 to-10.30 (kJ/mol) for Godume shahri seed gum, respectively.
Behrooz Alizadeh Behbahani; Ali Alghooneh; Farideh Tabatabaei Yazdi; Fakhri Shahidi; Mohebbat Mohebbi
Abstract
Introduction: Avicennia marina, commonly known as gray or white mangrove, is a specie of mangrove tree classified in the plant family Acanthaceae. It is distributed along Africa's east coast, south-west, south and south-east Asia, and southern Iran along the Persian Gulf coast. It grows as a shrub or ...
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Introduction: Avicennia marina, commonly known as gray or white mangrove, is a specie of mangrove tree classified in the plant family Acanthaceae. It is distributed along Africa's east coast, south-west, south and south-east Asia, and southern Iran along the Persian Gulf coast. It grows as a shrub or tree to a height of three to ten meters. Mixture design is one of the most popular smart systems which is based on simulation of linear and non-linear systems using mathematical and statistical techniques, and a useful tool for dealing with completely unknown systems. Chemical preservatives are commonly used for inhibition of pathogens in foods, people are concerned about the side effects of preservatives on their health. Replacement of chemical preservatives with natural substances have a great importance in food preservation. Natural preservatives, as well as, essential oils and plant extracts are suitable alternatives for chemical preservatives. The main purposes of this study are the evaluation of the effects of different combinations of four solvents (water, ethanol, methanol and glycerin) on the efficiency of mangrove leaf extraction using response surface method with mixture optimal design, the optimization of solvent formulation for mangrove leaf extraction, and, finally, the evaluation of the in vitro inhibitory and bactericidal effects of mangrove leaf extract on Listeria innocua ATTC33090 ، Enterococcus faecium ATTC 51559 and Escherichia coli ATTC 25992.Materials and method:Fresh mangrove leaves were prepared from Qeshm Island, Persian Gulf, Iran, in August 2012. Water, ethanol, methanol and glycerin extracts were prepared by adding 50 g of powdered mangrove leaf to 250 mL of the solvent. Extraction was carried out for 48h, in ambient temperature. The mixture of extract and leaf powder was separated by Watman filter paper, then the filtrate was centrifuged in 3000g for 10 minutes and filtered using a 0.45 µm Millipore filter. Finally, in order to separate the solvent and concentrated extract, the solutions were evaporated using a rotary vacuum evaporator. The concentrated extract was stored in dark aluminum containers at 4°C. In this study, the effects of water, ethanol, methanol and glycerin at five levels (0, 31.25, 83.33, 125 and 250 ml) on efficiency of mangrove leaf extraction by mixture optimal design has been investigated. Modeling and optimization has been carried out by Scheffe polynomial. The antimicrobial activity of mangrove leaf extract was evaluated using disk diffusion method. The minimum inhibitory concentration (MIC) of mangrove leaf extract was determined using serial dilution tubes. For each extraction method (based on solvent, Water, Ethanol, Methanol and Glycerin), 8 serial concentrations (2, 4, 8, 16, 32, 64, 128, 256 mg/mL) and 1 control tube of mangrove leaf extract were prepared in Mueller-Hinton broth. The minimum bactericidal concentration (MBC) of mangrove leaf extract was determined using serial dilution tubes.Results and Discussion:The Results indicated that Scheffe polynomial model was highly significant for prediction of efficiency of mangrove leaf extraction (R2 and R2adj values equal to 0.940 and 0.8447, respectively and The lack-of-fit tests did not result in a significant, also F-value (14.62) indicated that the model is sufficiently accurate). The optimum formulation was found as following: glycerin (0 ml), water (28.22 ml), methanol (59.83ml) and ethanol (161.95 ml) respectively. Maximum of antimicrobial effect on Listeria innocua and highest resistance against mangrove leaf extract on Escherichia coli were observed. Increasing concentration of mangrove extracts had a significant effect (p< .05) on inhibition zone diameter. This may have been resulted from the increment of the solvent polarity associated with glycerin increase. In order to study the mentioned hypothesis, Pearson Square statistical test was used to determine the correlation between the extraction rate and polarity. The results showed that a significant (P≤0.05) and inverse relationship between the extraction rate and polarity of the solvent. Moreover, in order to check the accuracy of the model fitted on the data obtained from mangrove leaf extraction rate the goodness of fit was investigated using both coefficient of determination (R2) and lack of fit test. A 94% coefficient of determination and lack of significance (P≤0.05) for lack of fit test suggested that Schef model could accurately fitt the data and predict it The results of this study showed that Schef polynomial and numerical optimization using mixture design method were suitable to fit efficiency of mangrove leaf extraction and solvent formulation optimization data, respectively. According to the results, the optimized solvent formulation was glycerin (0 mL), water (28.22 mL) and ethanol (161.95 mL). Conclusion: Finally, the results showed that mangrove leaf extract had a notable antimicrobial effect on the studied strains “in vitro”. More “in vivo” studies seem to be required in order to determine the best extract dosage which leads to inhibition of microbial infection.
Azam Ayoubi; Nasser Sedaghat; Mahdi Kashani-Nejad; Mohebbat Mohebbi; Mehdi Nasiri mahalati
Abstract
The purpose of this research was study effect of drying conditions (temperature at three levels of 60,70, and 80 oC, air velocity at two levels of 1/5 and 2/5 m/s, and four pretreatments including potassium carbonate and paksan oil, olive oil, hot water and no pretreatment (control)) on drying grape ...
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The purpose of this research was study effect of drying conditions (temperature at three levels of 60,70, and 80 oC, air velocity at two levels of 1/5 and 2/5 m/s, and four pretreatments including potassium carbonate and paksan oil, olive oil, hot water and no pretreatment (control)) on drying grape process and quality of raisin including rehydration, shrinkage, hardness and browning index. The results showed that temperature, air velocity and pretreatment have significant effects on drying rate and quality of raisin. Drying rate increased with increasing temperature and air velocity and with application of preatreatment. The best values of hardness (0.73 N), shrinkage (81/04%) and the least value of browning index (0/157) were related to dried raisin at 60 oC and most value of rehydration (1/266) was related to dried raisin at 70 oC. Air velocity just significantly affected on browning index. Increasing air velocity decreased browning index. Also between used preatreatments , potassium carbonate and paksan oil caused best physicochemical results.
Saeed Mirarab Razi; Mohebbat Mohebbi; Mohammad Hossein Hadad Khodaparast; Arash Koocheki
Abstract
Introduction: Proteins are widely used in food industry because it has functional properties such as formation and stabilization of foam systems. These molecules had surface-active properties. They rapidly adsorb at interface during the foaming processes and form a film around gas bubbles. The bulk properties ...
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Introduction: Proteins are widely used in food industry because it has functional properties such as formation and stabilization of foam systems. These molecules had surface-active properties. They rapidly adsorb at interface during the foaming processes and form a film around gas bubbles. The bulk properties has important role in the stabilization foam system. It has been shown that protein adsorption is influenced by molecular properties, such as size, shape, surface hydrophobicity, conformation, and charge and conditions in the bulk solution, such as bulk concentration, pH and ionic strength. The foaming properties depend on many intrinsic factors (size, structure of protein, hydrophobicity, surface potential, charge, etc.); and environmental and processing factors (protein concentration, pH, temperature, addition of other ingredients, etc.) Foams are colloidal systems in which gas phase dispersed in an aqueous continuous phase. Foaming operation is usually devoted to produce lighter products, modify the appearance and the texture of food products, therefore, it be used to production new products adapted to consumer choice and needs, using air as a zero-cost component. Microstructure has fundamental role in foam properties. At foam based products, bubble size is of most importance at the foam properties, because it influences on texture, the mouth-feel and the stability of the aerated product. Many food products have aerated structure. In these foods, the gas phases, forms small bubbles that modify microstructure and mouth feel properties of product. Aerated desserts have shown a great market potential, which is dependent on consumer behavior, interested in lighter and healthier products. Food products based on foam structure such as chocolate mousse have good marketing; therefore deep knowledge about their properties is important. Mousse is an aerated dessert with stabilized foamy structure which little attention has been paid to industrial production. Although, the most popular mousse flavor is chocolate, orange, lemon and strawberry have good marketability.Materials and method: This study follows two important objectives; first, the effect of different amount of gelatin concentration and sodium caseinate on rheological, physical and sensory properties of chocolate mousse is investigated. Then, the relationship this parameters was discussed on the basis of laboratory results using PCA method. Chocolate mousse was include of, Gelatin(Bangladesh, type B, bloom 160-180), Cacao powder(Cargill Co., Netherlands), Whipped cream(Mahrang sahar shargh CO., Iran 27% fat), Sugar(Fariman, Iran) and Sodium caseinate (Milad, Iran). Chocolate mousse samples were prepared with different amount of gelatin (1, 2 and 3 gr) and sodium caseinate (1, 2 and 3 gr) concentrations. Gelatin was first dissolved in hot water. Next, cacao powder and sugar were stirred in hot water and added to whipped cream agitated by Gosonic home mixer with speed 5400 RPM for 3 minutes. Then, Sodium caseinate was mixed in distilled water for 2 minutes and added to mixture prepared. Finally, mousse was placed in refrigerator after stirring with gelatin solution. The samples were stored in a refrigerator for 24 hours.Results and Discussion: In this work, physical, sensorial and rheological properties of chocolate mousse were investigated. Rheological measurements were carried out using a rotational viscometer (Bohlin Model Visco 88, Bohlin Instruments, UK) equipped with a heating circulator (Julabo, Model F12-MCand, Julabo Labortechnik, Germany) and C30 spindle. All the experiments were performed at 25°C±0.2. A pre shearing of 10-15 s at 14.1 s was applied to all samples. Sample flow was measured by registering the shear stress/ shear rate data at an increasing trend from 14.1 to 300 s. To describe the time independent flow behavior, the experimental data (shear stress-shear rate) were fitted by Herschel- Bulkley, Bingham, power law, and Casson models. Sensorial properties were tested at the same optical condition and environmental temperature. Chocolate mousses were evaluated using hedonic analysis procedures by a sensory panel of ten assessors, who had been selected and trained. Sensorial properties were evaluated based on 1 to 9 scores. The gas hold-up was calculated by comparing the density of the aerated chocolate with the gas-free density of solid chocolate. PCA method was used for determination of the relation of sensory attributes and main component.Conclusion: Results showed that chocolate mousse incorporating 2 gr gelatin and 3 gr sodium caseinate had the best sensory properties. According to the R2 (R2>0/99) and RMSE values, it is obvious that the Power-law models can properly describe non-newtonian flow behavior of samples. Behavior index (n) and consistency coefficient (k) were obtained from fitting power-law model. Consistency coefficient was high in the sample containing 3 gr gelatin and 3 gr sodium caseinate. Density values decreased with increase in protein content and decrease in gelatin content. Based on PCA results, total acceptance of samples was severely related to the smoothness, jelly and melting rate attributes.
Esmail Khazaei; Fakhri Shahidi; Seyed Ali Mortazavi; Mohebbat Mohebbi
Abstract
Introduction: Kiwifruit (Actinidia sp.) has many appealing properties for consumers such as flavor, color, and nutritional content, especially vitamin C. Kiwi seems to be used as one of the major ingredients within the formulation of this category of foods.Microalgae are nutritional and innovative natural ...
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Introduction: Kiwifruit (Actinidia sp.) has many appealing properties for consumers such as flavor, color, and nutritional content, especially vitamin C. Kiwi seems to be used as one of the major ingredients within the formulation of this category of foods.Microalgae are nutritional and innovative natural sources that can be used in the development of novel foods. Among the known species of algae, Chlorella vulgaris and Spirulinaplatensis are common edible microalgae that have no side effects on health of human. The amino acid, carbohydrate, and fatty acid profiles of these microalgae are very similar to those of other food materials. Spirulina is a multicellular filamentous blue-green microalga, which was introduced as generally recognized as safe (GRAS) after being approved by food and drug administration (FDA). Spirulina can also be incorporated into common food preparations such as pastas, biscuit, bread, snack,pastille, candy, yoghurt, soft drink, causing health-promotion that are associated with microalgae biomass.The aim of this study was to investigate the possibility of producing new product based on kiwifruit and its enrichment with Spirulinaplatensis microalgae so that this product could replace common snacks, especially the pastilles containing synthetic colors and flavors, which have increasingly been used day by day despite having a low nutritional value and causing a variety of side effects. The role of pHysicochemical and sensory properties is very important in producing new products which can help producers design the products suitably. Therefore, some of the pHysicochemical properties of the kiwi base pastille were examined in this study, as well as the formulation and enrichment of it with Spirulinaplatensis. Material and methods: The ingredients of the formulations consist of 65% w/w kiwifruit puree, 30% w/w sweeteners (sugar, powdered glucose, invert syrup and sorbitol), 0.25% w/w high methoxyl pectin, 0.5% Agar, 0.5% Guar and Spirulinaplatensis(0, 0.25, 0.5, 1 and 2% w/w) as well.In order to produce fruit pastille based on kiwifruit puree, the kiwifruits were fist washed up, peeled and cut into pieces. Then the pieces were grinded. The prepared puree was mixed with Spirulinaplatensis, hydrocolloids and sweeteners at 70°C with specific ratios. Agar was dissolved in distilled water at 90°C and added to the concerned mixture. Finally, after moderating pH to 3.4 by adding 40 M citric acid and controlling the Brix degree in constant Brix of 45, the mixture was prepared. The mixture was then poured into stainless steel mesh molds with cavity dimensions of 1.2 cm × 2 cm × 2 cm and the molds were kept at 4°C for 2 hours to form the gel. Then the obtained gel was taken out of the mold cavities and the samples were dried at 70°Cfor 6 hours in a hot air drier with 1.5 m/s airflow rate. Then the regarded tests were performed on the dehydrated samples. To measure pH, pH meter (Hana, Portugal) was used. The measurement of mixture Brix was performed by an optical refract meter (Carlze, Germany). The drying process of the samples was conducted in a hot air drier (Soroush Medicine Co. Iran).Moisture, protein, fiber, lipid, ash, vitamin C, calcium and iron elements were measured according to the Iran national standard.Texture profile analyzer (QTS25 CNS Farnell England) equipped with a software was used to determine the textural properties of the samples. Samples were compressed and decompressed in two reciprocating cycles by a round plate cylindrical probe with 3.5 cm diameter, 1 mm/s probe speed and 5 g force to 30% initial height.Histological properties obtained from force-deformation curve are as follows: Hardness, Cohesiveness, Elasticity, Adhesiveness and Chewiness.Sensory test was performed with the judgment of 10 trained panelists. In order to evaluate the samples. A 9-point Hedonic method (1: very undesirable - 9: very desirable) was used. 5 sensory attributes (color, texture, flavor, odor and overall acceptance) were evaluated.SPSS software was used for the statistical analysis of the parameters. Mean of the replicates were compared via the multi-range Duncan`s test at 95% confidence level.In order to pHotograpHy with Scanning electron microscope, initial preparation should perform on all of samples.The obtained sampleswas removed from the templates and were sectioned on a scale of 2×1×1mm. samples were dehydrated in ethanol solution and then dried in a critical point. Then samples with 30 nm of gold/palladium coated and were tested using SEM (model LEQ1450VP) in the maximum voltage of 15 kv. At least four images with magnification of 500, 1000, 2000 and 5000 were prepared in several different areas of the samples.Results and discussion: The obtained results indicated that the effect of Spirulinawas significant on the moisture content and increasing Spirulinaconcentration led to increased moisture content of the product.The results of texture profile analysis indicated that the hardness and chewness was increased, but the cohesivness of samples was decreased when the amount of Spirulina is increased. The amount of protein, vitamin C, total ash, iron and calcium was increased by increasing the amount of Spirulina. SEM microscopic results showed that adding up Spirulina is led to the reduction of the uniformity of sample’s structure and then the gel matrix will be created with a larger pore. Results of sensory analysis indicate that samples containing 0.25% Spirulina have sensory characteristics (color, aroma, flavor and overall acceptability) than other samples.
Azam Ayoubi; Nasser Sedaghat; Mahdi Kashani-Nejad; Mohebbat Mohebbi; Mehdi Nasiri mahalati
Abstract
Introduction: Raisin is a principal traditional export product of Iran and has a special position in the foreign trade of the country.During storage, the product turns sticky and hard due to exudates syrup and moisture loss. To solve this problem, the application of edible coating would be an appropriatesolution. ...
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Introduction: Raisin is a principal traditional export product of Iran and has a special position in the foreign trade of the country.During storage, the product turns sticky and hard due to exudates syrup and moisture loss. To solve this problem, the application of edible coating would be an appropriatesolution. Edible coating may enhance the boundary layer resistance resulting to the enhanced shelf life of the product. Edible coatings are thin layers of edible materials applied to the product surface in addition to or as a replacement for natural protective waxy coatings and provide a barrier to oxygen, water and solute movement. They are also applied in foods to minimize the migration of components within the food systems or between the foods and their surrounding environment. They are used directly on the food surface by spraying, dipping or brushing to create a modified atmosphere. There are different kinds of films which are used such as polysaccharide, protein, lipid and composites. Lipid based coatings are primarily used for their hydrophobic properties which make them good barriers to water loss. In addition to preventing water loss, lipid coatings have been used to improve appearance by generating a shiny coverin fruits and vegetables, and to decrease respiration, thereby extending shelf life. The moisture barrier properties of hydrophilic coatings can sometimes be improved by addition of lipid materials The purpose of this research was to study the effect of lipid based edible coating (glycerylmonoestearate and carnauba wax) on physicochemical and microbial properties of raisin. Material and methods: Raisin samples (cvAskari)were dried usingsoda oil method and treated with coating materials based on lipid with essential oil of thyme (thymus vulgaris).Glycerylmonoestearate, carnauba wax and tween 80 were purchased from Sciencelab, Sigma-Aldrich and Merck Co. respectively. Raisinswerecoated with the following coating solutions: -Aqueous solution of tween 80 (0.5% w/w) -Aqueous solution of glycerylmonoestearate (0.5% w/w), tween 80 (0.5% w/w) -Aqueous solution of glycerylmonoestearate (0.5% w/w), tween 80 (0.5% w/w), 150 ppm essential oil of thyme -Aqueous solution of carnauba wax (0.5% w/w), tween 80 (0.5% w/w) -Aqueous solution of carnauba wax (0.5% w/w), tween 80 (0.5% w/w), 150 ppm essential oil of thyme Control sample was treated with aqueous solution of tween 80 (0.5% w/w).Distilled water was used for preparing all of coating solutions. Coating solutions were stirred and heated to 75oC (melting point of coating materials) for 30 min on a hotplate with a magnetic stirred to obtain uniform solutions. Dipping technique was used for coating of raisins. The coated raisins were placed on a basket to drip off residual coating solution and were dried in 25oC. The raisin smples were packaged in a 3 laminatedlayer bags (PE/PA/PE) with thickness of 80µ by Henkelman packaging machine and were stored at20, 35 and 50oC for 12 weeks. During the storage period, moisture content, water activity, hardness, color parameters (L*(lightness), a*(redness) and b*(yellowness)), percent of pestilence and microbial properties (total count, mold and yeast) were evaluated. Hardness of raisins was determined in apuncture test using a QTS texture analyzer (CNS Farnelll, Essex, UK) equipped with a needle probe (stainless steel cylinder of 2 mm of diameter with a conical needle bit) and a test speed of 60 mm. min−1 during the test. Hardness was defined as maximum force to puncture raisin from the top to a 2mm depth (Rolleet al. 2011).For colormeasurement, raisins were placed in to a black wooden box (interior size of 0.5 (width) × 0.5 (length) × 0.8 (height) m3 and were illuminated using 3 fluorescent tube lights (10W, 6500K; 40cm in length). A digital camera (Canoon EOS 1000D, Powershot, Taiwan) was located vertically at a distance of 20cm from the raisin surface. The images were preprocessed by Adobe Photoshop software, version 5.5. The Color properties were analyzed using ImageJ software, version 1.44o. The experiments were factorial with a completely randomized design. The coating material, temperature and storage time were the independent variables. Analysis of variance (ANOVA) was conducted for data using MSTAT-C software, version 1.42 (Michigan State University). Differences among the mean values were also determined using Duncan’s Multiple Range test. A significant level was defined as a probability of 0.05. The experiments were carried out on 4, 8 and 12 weeks after storage with three replications. Results and discussion: Results showed that coating, temperature and storage time would have considerable effect on the physicochemical and microbial properties of raisin. Coating caused decreasein moisture loss, hardness, lightness and redness. Increasing temperature and storage time increasedmoisture loss and hardness. Minimum hardness values were measured for 20 oC and 4 weeks storage and maximum hardness values were related to 50 oC and 12 weeks storage. Also it seems that increasing temperature and storage time influences thehardness by increasing moisture loss. Increasing temperature and storage time significantly decreased L* (p≤0.01). Increased enzymatic browning in raisins with increasing temperature was accompanied by an increase in a* value, and a decrease in b* value and caused to presenting dull colors. Total count, mold and yeast of coated samples decreased during storage period. Carnauba wax was more effective than glycerylmonoestearate on stability of raisin. Essential oil of thyme also caused improving color and microbial properties. Least values of redness (-2), total count (2.06 log cfu/g) and mold and yeast (1.32 log cfu/g) were related to carnauba wax coating with essential oil of thyme.
Hamed Mahdavian Mehr; Arash Koocheki; Mohebbat Mohebbi
Abstract
Introduction: Batter coating is a new technology to reduce fat content of fried foods. The ingredients and flowproperties of batter are the most important parameters to determine the performance of batter coating and quality of the final product. Among batter additives, proteins can be used as an important ...
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Introduction: Batter coating is a new technology to reduce fat content of fried foods. The ingredients and flowproperties of batter are the most important parameters to determine the performance of batter coating and quality of the final product. Among batter additives, proteins can be used as an important and effective component, because of their emulsifying properties, water absorption, and barrier properties. Previous studies have shown that soya protein isolate (SPI) is a very good hydrophilic protein which could be used to control the viscosity of batter. The batter temperature has direct effect on its flow behavior's properties and has a major impact on the quality of final coated product. Therefore, the aim of the present study was to evaluate the effects of temperature (5, 25 and Cº45) and SPI content (2 and 4%), on flow properties of the batter and quality of deep-fried chicken nuggets. Materials and methods:Raw materials such as fresh chicken breasts, onion, salt, hot pepper, wheat flour, baking powder, and 100% pure sunflower oil were purchased from local markets. SPI (92% protein) were obtained from GolharKhorasanRazavi Company. The batter formulations consisted of wheat flour, salt (1.5% w/w, db), baking powder (0.5% w/w, db) and SPI (2 and 4% w/v, db). For all samples, water/dry mix proportion had always been 5:3. Rheological properties of the batters were carried out using a Bohlin rotational viscometer. For each test, shear rate increased from 0 to 300 s−1, followed by a logarithmically decrease from 300 to 0 s−1. The flow behavior index (n) and consistency coefficient (k) values were computed by fitting the power law model, and time dependency properties of the batters were obtained from the area between the upward and downward curves. Temperature dependency of consistency coefficients were assessed by fitting the Arrhenius model. The batter coating on the chicken substrate was appliedat three temperatures (5, 25 and 45 Cº), and batter pickups (%) were calculated by the weight difference between the chicken nuggets after coating to the weight of chicken nuggets before coating. Coated samples were stored at -18 Cº for two weeks. After thawing, chicken nuggets were fried at 180°C for 3 min in sunflower oil using a programmable deep fat fryer. The influence of SPI concentrations and batter temperature on color and crust adhesion of deep-fat fried chicken nuggets was measured with image processing. In brief, images were taken by a digital camera under controlled conditions, and then analyzed by Image J software. The Percentage of adhesion (CRA), obtained by calculating the ratio of the pixels corresponding to the perimeter of the substrate where coating is adhered to the pixels corresponding to the total perimeter of the substrate. The color of deep-fat fried chicken nuggets were examined in terms of L*, a* and b*values. Oil and moisture content of the chicken nuggets was determined by standard techniques. Results & Discussion: Results showed thatall samples had a shear-thinning behaviour at all batter temperatures (n≥0.539). Power law model was adequately suitable to describe the flow behavior of the batters (R2≥0. 994). The activation energy was between 5.106 to 5.630 (kj/mol).Addition of soy protein isolates into the batter, enhanced the time dependency, whereas, the increase of temperature decreased the hysteresis area. The relative increase in apparent viscosity with increasing SPI might be attributed to the high capacity of SPI to absorb free water. However, decrease in apparent viscosity and time dependency of batters with increasing the temperature could be due to the intermolecular interactions in batter system. An increase in temperature weakens the intermolecular interactions and increases the mobility of macromolecules which reduces the batter resistance to shear force. The batter temperature and formulation had significant effect on the batter pickup. This effect was mainly due to the changes occur on flow properties of batter. Using SPI increased the a* and decreased the L* of the final product. This could be due to the active participation of SPI in the Millard reaction. The data obtained for crust adhesion revealed that the increase in SPI concentration lead to a decrease in batter adhesion to the crust. In other words, the ability of soya proteins to form film during early time of frying reduces the moisture migration from the substrate to oil, which creates a positive pressure in the inner layer of crust and reduces the adhesion. Conclusion: Chicken nuggets coated with batter containing SPI had higher moisture and lower oil content than the control sample. Finally, the change in batter temperature had no significant effect on the crust adhesion and oil and water content in the final product.
Mohsen Zandi; Mohebbat Mohebbi; Mehdi Varidi; Navid Ramazanian
Abstract
.Introduction: Flavor release from food during consumption in the mouth plays an important role in flavor perception and influenced by the food matrix. Since, food matrix changes biochemically and physically during eating, therefore, food flavor microencapsulation results in controlled release at specific ...
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.Introduction: Flavor release from food during consumption in the mouth plays an important role in flavor perception and influenced by the food matrix. Since, food matrix changes biochemically and physically during eating, therefore, food flavor microencapsulation results in controlled release at specific situations. On the other hand, stability and availability of flavors are affected by food processing and storage. To control the flavor release at specific condition during consumption or stability and availability during food processing and storage; it is essential to encapsulate flavor components before use in food complex. Encapsulation is the term for a collection of technique that used as delivery of active and bioactive parts. This novel technology enables isolated of gases, liquid droplets, or solid particles in the core of microscopic vesicular system with porous or non porous semi permeable shell that release occurs in response to the specific situations. Controling release of active compound depends on microcapsule characteristics such as pore size, mechanical stability of the colloidal shell, shell thickness and shell permeability; molecular size and solubility of active parts in the shell and properties of the release media including shear force, temperature, pH, ionic strength, etc. This paper presents the formation and characterization of novel diacetyl encapsulated alginate-whey protein concentrate (AL-WPC) microcapsules. Diacetyl release was investigated at simulated mouth condition in different ratios of artificial saliva (0, 1:4 and 1:8) and three various oral shear rates (0, 50 and 100 s-1) and the diffusion coefficient was estimated using Fick’s law. The main aim of this work was to develop a prediction model to study the flavor release from microcapsules. Materials and Methodes: Aiming to show the applicability of our agent-based model platforms, the release of 2,3-butanedione (diacetyl) from alginate-whey protein concentrate (AL-WPC) microcapsules was used as a case study to validate our simulation model based on NetLogo platforms. For this purpose, our previous work on evaluation of diacetyl encapsulated alginate-whey protein microspheres release kinetics and mechanism at simulated mouth conditions was used (Zandi, M., Mohebbi, M., Varidi, M., Ramezanian, N., 2014). In previous our work, encapsulated diacetyl release was measured at three oral shear rates (0, 50 and100 s-1) and various ratios of saliva to microcapsule (0, 1:4 and 1:8) simulating mouth conditions. Then, experimental release data were fitted using different kinetic models. It was found that release from these microcapsules followed a classical Fickian diffusion. We use release data for calculating release rate. For model validating, diffusion equation was fitted to the experimental data, and diffusion coefficient was obtained for diacetyl release at various mouth conditions. To this purpose, the following model was obtained by solving unsteady diffusion equation in spherical coordinate:(M(t))/M_0 =100-exp(-(3×D×(R+b))/(R^2×b)×t) (1)where M (t) and M0 are the diacetyl release at time t and 0 respectively, R is a microcapsules radius (m), t is time, D is the diffusion coefficient and b is the shell thickness (m). We also use diffusion coefficient to calculate permeability for each specific condition by equation (2): P=(D×K)/b (2)Where P is the permeability coefficient, D is the diffusion coefficient and K is the partition coefficient.Finally, the model and experimental data were analyzed using Matlab software (R2007).Result and Discussion: In our study, AL-WPC microcapsule was fabricated by emulsification/internal gelation method, and diacetyl was loaded into microcapsule. Most of microspheres had a completely spherical shape with smooth surface, and range in size from 20-150 μm. The diacetyl encapsulated microsphere had a porous and smooth shell with some holes that caused the quicker diacetyl release initially. The mean hydrodynamic diameter 112.8 ± 0.9 μm (mean value ± SD for n= 2) was measured via particle size analyzer (DLS). the high efficiency of 79.34% was obtained for diacetyl encapsulated AL-WPC microcapsule. About 20% of diacetyl was loosed because of the solubility and volatility of the diacetyl molecule (diacetyl is a low molecular weight and water soluble component).. Conclusion: It was showed that the shear rate of release media had a significant (p
Seyed Amir Tavakoli Lahijani; Fakhri Shahidi; Mehdi Varidi; Mohebbat Mohebbi
Abstract
Spirulina platensis is a blue-green microalga with unique nutrient content and several therapeutic aspects which has been used for fortification of different foods. In this study, the effect of Spirulina platensis powder in different levels (0, 0.5, 1 and 2 percent), added in two stages (before pasteurization ...
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Spirulina platensis is a blue-green microalga with unique nutrient content and several therapeutic aspects which has been used for fortification of different foods. In this study, the effect of Spirulina platensis powder in different levels (0, 0.5, 1 and 2 percent), added in two stages (before pasteurization and at same time with starter culture) was studied on the microstructure and acidification characteristics of yogurt during fermentation time. The results showed that different levels of Spirulina biomass had significant effect on acidification kinetics parameters of yogurt samples (p
Mohebbat Mohebbi; Elham Mahdian
Abstract
Foaming conditions of the red beet (Beta vulgaris L) puree were optimized using response surface methodology (RSM) with respect to Arabic gum concentrations (0.01 – 0.4% w/w), red beet puree (40 _ 60% w/w),egg white concentration( 5 _ 15% w/w) and whipping time (3 – 9 min) for minimum foam ...
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Foaming conditions of the red beet (Beta vulgaris L) puree were optimized using response surface methodology (RSM) with respect to Arabic gum concentrations (0.01 – 0.4% w/w), red beet puree (40 _ 60% w/w),egg white concentration( 5 _ 15% w/w) and whipping time (3 – 9 min) for minimum foam density and foam drainage volume as response variables. Foams were prepared from various pulp concentrations by adding various concentrations of egg white as foaming agent and Arabic gum as stabilizer at different whipping time. The optimized conditions after the numerical and graphical optimization for maximum stability and minimum foam density were found at Arabic gum (0.29% w/w), egg white (15% w/w), red beet Puree (60% w/w), and whipping time (9 min).The results showed that the stability of foams increased with increasing Arabic gum concentration( p
Hadi Bagheri; Mohebbat Mohebbi; Arash Koocheki
Abstract
The effect of wheat-sorghum flour ratio (0, 25, 50, 75 and 100%) on viscoelastic and farinographic behaviour of dough was investigated. Constants of Peleg - Normand model and the stress relaxation (% SR) was calculated for the variables and the correlation between farinograph characteristics and stress ...
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The effect of wheat-sorghum flour ratio (0, 25, 50, 75 and 100%) on viscoelastic and farinographic behaviour of dough was investigated. Constants of Peleg - Normand model and the stress relaxation (% SR) was calculated for the variables and the correlation between farinograph characteristics and stress relaxation test parameters were evaluated. The results showed that with increasing the ratio of sorghum in flour, the amount of initial force (F0), mixing tolerance index and the stress relaxation (% SR) increased. However, the rate of water absorption, dough stability and Peleg - Normand model parameters (K1 and K2) decreased with increasing substitution of sorghum flour. Survey results showed that the correlation between the parameters of water absorption, dough stability and K1 and K2 was a highly positive. The stress relaxation (% SR), mixing tolerance index and the initial force (F0) had also positive correlations. With increasing substitution of sorghum flour, dough indicated the liquid-like viscoelastic behavior. Fitting the experimental data with the model showed the efficiency of Peleg - Normand model at high strain (10%).
Sepideh Amirabadi; Arash Koocheki; Mohebbat Mohebbi
Abstract
In this research, different concentrations of xanthan and Lepidium perfoliatum seed gums (0.1, 0.2 and 0.3%) were used to improve the quality and shelf-life of chiffon cake. For this purpose, specific gravity and apparent viscosity of batter, and the volume, specific volume, moisture, sensory and texture ...
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In this research, different concentrations of xanthan and Lepidium perfoliatum seed gums (0.1, 0.2 and 0.3%) were used to improve the quality and shelf-life of chiffon cake. For this purpose, specific gravity and apparent viscosity of batter, and the volume, specific volume, moisture, sensory and texture properties, crumb and crust color were examined. To investigate the effect of gums on the shelf-life, all cakes were stored for sixth days. Results showed that there were a positive correlation between viscosity of batter and cake volume. Both gums improved chiffon cake properties after removing from the oven and during storage. It was found that using 0.1% xanthan gum increased the cake volume, cohesiveness and sensory scores, decreasing firmness and moisture loss during storage of cake.
Farideh Tabatabaei Yazdi; Mohebbat Mohebbi; Seyed Ali Mortazavi; Arash Ghaitaranpour; Behrooz Alizadeh Behbahani
Abstract
The effects of a couple of factors (cooking period of wheat: 0, 1 and 3.5 h and temperature of drying 70, 80 and 90 ْC) on drying behavior of Tarkhineh during hot-air drying has been investigated. Tarkhineh pill samples with 8 cm diameter and 11 mm thickness were dried to 0.64(d.b). Results showed that ...
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The effects of a couple of factors (cooking period of wheat: 0, 1 and 3.5 h and temperature of drying 70, 80 and 90 ْC) on drying behavior of Tarkhineh during hot-air drying has been investigated. Tarkhineh pill samples with 8 cm diameter and 11 mm thickness were dried to 0.64(d.b). Results showed that cooking of wheat led to higher water absorption of Tarkhineh dough, while increased drying rate. On the other hand, increasing drying temperature resulted in higher drying rate of samples. The effects of temperature on drying rate was pronounced in raw samples compared to cooked ones, which could be attributed to the cracking in the cooked samples during drying . Drying kinetics of Tarkhineh in raw samples unlike cooked samples presented a falling rate period followed by a constant rate period. The effective moisture diffusion coefficient of Tarkhineh varied between 1.611E-10 & 7.822E-10 (m2/s)) for the given temperature range) and corresponding activation energy was between 37.928 and 17.941(kJ/mol) respectively.
Behdad Shokrollahi Yanchedhmeh; Mohebbat Mohebbi; Mehdi Varidi; Elham Ansarifar
Abstract
In recent decades, as the result of industrial life, consuming fried and fast foods have increased significantly. Excessive use of fat, especially saturated fats and trans fatty acids is one of the important factors that increases heart diseases, weight gain, and cancers. Therefore, using effective methods ...
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In recent decades, as the result of industrial life, consuming fried and fast foods have increased significantly. Excessive use of fat, especially saturated fats and trans fatty acids is one of the important factors that increases heart diseases, weight gain, and cancers. Therefore, using effective methods for decreasing fat absorption not only retains desirable features but also seems essential. In this study, the effect of subtituting wheat flour with lentil flour on the batter formulation (in different level of 10, 25 and 50 percent) on the rheological properties of batter, amount of moisture and oil content, and color of fried crusts investigateded by using a deep-fried crust model at three temperature (140, 160 and 180oc) and for 90, 180, 270 and 360 s frying times. Consistency index showed a significant increase by increasing subtitution of lentil flour in batter formulation. Moreover, all the batters showed shear-thinning behaviour. The findings indicated that Batter formulations, temperature and frying time significantly (p < 0.05) affected moisture content, oil content and color of fried Crusts. Results of the study indicated that as frying time increased, the amount of moisture content reduced and increased the oil content of the final product. Also, with increasing substitution of lentil flour, moisture removal decreased and therefore, oil uptake decreased. 50% lentil flour substituted samples was found to be an effective formulation in decreasing oil content of fried crusts at all the times . Conrol sampel showed the lowest moisture content and highest oil content among all the formulations. 50% lentil flour substituted samples was found to be an effective formulation in decreasing oil content of fried crusts at all the times . Conrol sampel showed the lowest moisture content and highest oil content among all the formulations. Temperature leaded to an increase in moisture removal and an increase in oil content. By increasing frying time, temperature and subtitution of lentil flour in battre formulation, L*parameter decreased and a* and b* increased.
Mohammad Bagher Habibi Najafi; Mohebbat Mohebbi; Fakhri Shahidi; Seyed Ali Mortazavi
Abstract
The effect of pretreatment osmotic-ultrasonic dehydration on the drying kinetic, rehydration kinetic, texture, shrinkage and color change of quince slices was investigated. Quince slices were osmotic-ultrasonic processed at 27.25 min for ultrasonic time, 120 min for osmotic dehydration and 50.52 % for ...
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The effect of pretreatment osmotic-ultrasonic dehydration on the drying kinetic, rehydration kinetic, texture, shrinkage and color change of quince slices was investigated. Quince slices were osmotic-ultrasonic processed at 27.25 min for ultrasonic time, 120 min for osmotic dehydration and 50.52 % for sucrose concentration. The un-treated and pre-treated samples were then dehydrated at80°C. The effective diffusivity calculated by applying the Fick’s diffusion model. The pretreatment caused a decrease in Deff. Application of osmotic-ultrasonic dehydration reduced the sample hardness, color changes and shrinkage while it had increased the sample springiness, and chewiness.
Esmail Khazaei; Fakhri Shahidi; Seyed Ali Mortazavi; Mohebbat Mohebbi
Abstract
In this research, the production of a new kiwi- based product by applying kiwi puree, agar (0.25, 0.5 and 1%), guar (0.25, 0.5 and 1%) and other formulation ingredients (kiwi puree, sweeteners and pH modulators) has been investigated. Dependent variables include moisture content measurement, instrumental ...
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In this research, the production of a new kiwi- based product by applying kiwi puree, agar (0.25, 0.5 and 1%), guar (0.25, 0.5 and 1%) and other formulation ingredients (kiwi puree, sweeteners and pH modulators) has been investigated. Dependent variables include moisture content measurement, instrumental texture analysis and sensory evaluations were carried out in a factorial design and the means were compared at significance level of 5 % by Duncan test. The results indicated that guar had a significant effect on the moisture content of final product. Textural properties of the kiwi pastille were influenced by the type and amount of hydrocolloids. Synergistic effects of agar and guar on the textural properties were also observed. While all products were acceptable regarding sensory properties, the samples prepared with 1% agar and 1% guar obtained the highest score.
Ahmad Ehtiati; Fakhri Shahidi; Mohebbat Mohebbi; Masoud Yavarmanesh
Abstract
SMP was substituted by WPC in four levels for preparing reconstituted milk. Two ropy and one nonropy starter cultures was used for Doogh preparation. Yield stress, viscosity, consistency index and pseudoplastic behavior of Doogh increased by increasing WPC content. Results showed that WPC increased colloidal ...
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SMP was substituted by WPC in four levels for preparing reconstituted milk. Two ropy and one nonropy starter cultures was used for Doogh preparation. Yield stress, viscosity, consistency index and pseudoplastic behavior of Doogh increased by increasing WPC content. Results showed that WPC increased colloidal particles dimension and constructed a network which led to a decrease in Doogh phase separation (%32 at the highest level of WPC) during storage. Starter type had no effect on the Doogh stabilization. It does not have any effect on the studied physical properties in the presence of WPC, as well. Adding WPC to milk leads to improve of physical properties and stability of Doogh but using EPS producing starter cultures requires further studies in this field.
Mohebbat Mohebbi; Mohammad Hossein Hadad Khodaparast; Mehdi Varidi; Bijan Malaekeh Nikooei
Abstract
In this study, the oil yield, fatty acid (FA) composition and the physicochemical and quality characteristics of Salvia macrosiphon crude seed oil were determined. The main fatty acids ranked in the following order of abundance: α- Linolenic Acid> Linoleic Acid> Oleic Acid. The n3 /n6 FA ...
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In this study, the oil yield, fatty acid (FA) composition and the physicochemical and quality characteristics of Salvia macrosiphon crude seed oil were determined. The main fatty acids ranked in the following order of abundance: α- Linolenic Acid> Linoleic Acid> Oleic Acid. The n3 /n6 FA ratio and polyunsaturated FA/ Saturated FA ratio were 1.6 and 7.23, respectively. The FA composition revealed that the oil had great potential to use as nutritional dietary component and also was very susceptible to oxidation. The physicochemical properties such as Iodine ( 168.7 gI2/100g oil) , Acidic ( 0.5) and Peroxide ( 1.9) Value, color ( L: 59.22, a: -5.09, b: 22.94) and refractive index (1.4723) were also determined. Total phenol, tocopherol and sterol content were 165.22 mg GA/kg oil, 629.59 and 2540.6 ppm. In addition Oxidative Stability Index was 3.94 h.
Elham Ansarifar; Mohebbat Mohebbi; Fakhri Shahidi; Mehdi Varidi
Abstract
The objective of this study was to evaluate the effect of frying temperature, time and different batter formulations on the rheological properties and mass transfer during deep fat frying of Kurdish cheese nuggets. The effects of white egg (0, 5, 10%) addition to the batter formulation of cheese nuggets ...
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The objective of this study was to evaluate the effect of frying temperature, time and different batter formulations on the rheological properties and mass transfer during deep fat frying of Kurdish cheese nuggets. The effects of white egg (0, 5, 10%) addition to the batter formulation of cheese nuggets and frying at 150, 170 and 190◦C for 0, 1, 2, 3 and 4 min have been investigated. The results showed an interaction effect of these processing conditions on mass transfer. The most reduction in fat absorption was observed when samples were coated with batter containing 10% white egg and fried at 150 ◦C. The kinetic model based on the Fick’s law was used to describe moisture transfer data. The effective moisture diffusivity of batter without white egg was within the range of 3.97×10−8 and 7.51×10−8m2/s with R2 between 0.91 and 0.86 .In the samples coated with the batter including white egg, the effective diffusivity ranged between 2.26×10−8 and 5.96×10−8m2/s with R2 between 0.98 and 0.87, and fat transfer rate constant was between 1.1×10−3 and 8.9×10−3 s−1 with R2 from 0.82 to 0.99. Activation energy obtained from the Arrhenius plot for the effective moisture diffusivity of batter with and without white egg was 30.01 kJ/mol and ranged from 38.42 to 36.52 kJ/mol, respectively
Atena Pasban; Mohebbat Mohebbi; Hashem Pourazerang; Mehdi Varidi
Abstract
Enzymatic browning and formation of brown pigments are some of the most important problems in preparation of mushroom purees. In this study, the effect of some anti browning agents including sodium metabisulphite, ascorbic acid, and citric acid on the whiteness and foaming properties of mushroom purees ...
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Enzymatic browning and formation of brown pigments are some of the most important problems in preparation of mushroom purees. In this study, the effect of some anti browning agents including sodium metabisulphite, ascorbic acid, and citric acid on the whiteness and foaming properties of mushroom purees was investigated. The results showed that soaking with acids and sodium metabisulphite significantly (p
Fereshteh Dehghan Nassiri; Mohebbat Mohebbi; Farideh Tabatabaei Yazdi; Mohammad Hossein Hadad Khodaparast
Abstract
The objective of this work was to determine the effect of pre-frying elimination through the addition of methylcellulose and the influence of wheat flour partial replacement with corn flour (5 and 10%) on some quality factors of deep fat fried shrimp nuggets and compare the results with traditional process ...
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The objective of this work was to determine the effect of pre-frying elimination through the addition of methylcellulose and the influence of wheat flour partial replacement with corn flour (5 and 10%) on some quality factors of deep fat fried shrimp nuggets and compare the results with traditional process including pre-frying step. All batters showed shear-thinning behavior (n ≤ 0.624) and provided a good fit with power law model (R2 ≥ 0.979). Methylcellulose produced a significant increase in the consistency index of the batters. The highest pick-up value (57.68%) and the lowest oil content were found in 2% MC added batters that contained 5% corn flour, which was consistent with its high apparent viscosity. Results showed that the pre-frying elimination is an effective way in reducing oil content (%46) in deep fat fried shrimp nuggets.
Homa Baghaei; Farimah Aghaei; Nasser Sedaghat; Mohebbat Mohebbi
Abstract
In view of the importance environmental pollution caused by plastic food packaging, in recent years there is a considerable interest in edible films and coating based on polysaccharides, proteins, lipids or combination of them. Edible coatings also serve as carriers of food additives such as anti-browning ...
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In view of the importance environmental pollution caused by plastic food packaging, in recent years there is a considerable interest in edible films and coating based on polysaccharides, proteins, lipids or combination of them. Edible coatings also serve as carriers of food additives such as anti-browning and antimicrobials agents, colorants, flavor, nutrients and spices, so act as active packaging. In this study, effect of garlic essential oil )0.5%, 1.5%, 2.5% w/w of film solution) on isolated soy protein films was investigated by measuring changes in properties including antimicrobial activity against (Escherichia coli H7:0157, Salmonella enteritidis and Staphylococcus aureus), mechanical (tensile strength, elongation at break), physical (transparency, water vapor permeability, microstructure) and sensory (chewing, apparent and odor). Incorporation garlic oil improved mechanical and water vapor permeability properties and decreased transparency, structure and organoleptic attributes (p
Mohammad Reza Amiryousefi; Mohebbat Mohebbi; Faramarz Khodaiyan
Abstract
Analysis of food surfaces is of interest because many processes depend on their complexity. Food surfaces show several textural characteristics related to their nature, composition and processing. Food surface images and their microscopic details need to be translated into numerical data before engineering ...
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Analysis of food surfaces is of interest because many processes depend on their complexity. Food surfaces show several textural characteristics related to their nature, composition and processing. Food surface images and their microscopic details need to be translated into numerical data before engineering analysis. Fractal geometry is a novel concept to describe the complexity of natural shapes. In order to introduce a nondestructive method estimating the effect of process conditions on ostrich meat plates’ surface, in this research an image analysis technique was applied and the concept of fractal dimension was used to quantity the changes. Results show that fractal dimensions of the surfaces decreased with frying. Furthermore, with the increase in frying temperature, frying time and power of microwave pretreatment, a growing procedure in fractal dimension was observed. Fractal dimension as a quantity index could describe the shrinkage of deep-fried ostrich meat as a physical property.
Roya Rezaee; Fakhri Shahidi; Mohammad Elahi; Mohebbat Mohebbi; Mehdi Nasiri mahalati
Abstract
In this research, the production of plum pastille-like with starch and gelatin was studied. Thirteen formulation of plum pastille-like were prepared according to a second-order composite rotatable design (with five central points). Response surface methodology (RSM) was used to optimize product formulation ...
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In this research, the production of plum pastille-like with starch and gelatin was studied. Thirteen formulation of plum pastille-like were prepared according to a second-order composite rotatable design (with five central points). Response surface methodology (RSM) was used to optimize product formulation with: gelatin concentration ranging from 3.85 to 6.925 % (w/w), and starch concentration ranging from 0 to 3.85 % (w/w) as independent variables. The dependent variables were texture objective evaluation and total acceptance obtained from sensory analysis. The texture and flavor attributes of the samples were identified and evaluated by a trained descriptive panel. The thickeners strongly affected texture and flavor attributes of the samples. The resulting polynomial equation (R2=0.9325) revealed that a formulation with 5.38% gelatin and 3.85% starch had a maximum total acceptance.
Fakhri Shahidi; Mohebbat Mohebbi; Mohammad Noshad; Ahmad Ehtiati; Milad Fathi
Abstract
Banana is one of the most important tropical fruit from commercial and industrial point of view. This fruit is an extremely perishable fruit which can not be preserved using freezing process. Therefore, drying is the most promising method. Conventional air drying is energy intensive and consequently ...
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Banana is one of the most important tropical fruit from commercial and industrial point of view. This fruit is an extremely perishable fruit which can not be preserved using freezing process. Therefore, drying is the most promising method. Conventional air drying is energy intensive and consequently expensive method. Pre-treatments can be used to reduce the initial water content or to modify the fruit tissue which will result in higher yield with lower costs. In this research, the effect of osmotic dehydration and ultrasonic pre-treatment variables prior to air drying of bananas, including the type of solution (Glucose, Sucrose), time of immersion in osmotic solution (30, 45, 60 min), solution concentration (Brix 30 and 50), ultrasonication time (10, 20, 30 min) on water loss, solid gain, shrinkage, effective diffusivities and color in the process were studied. Results showed that the highest rate of water loss and solid gain and also the lowest rate of shrinkage were obtained in both pre-treatments when 50% glucose concentration was applied. The results indicated that unlike ultrasonication, osmotic pretreatment had a significant effect on color parameters of dried bananas.
Keywords: Banana, Drying, Image processing, Osmotic dehydration, Qualitative characteristics, Ultrasound